How to grow tomatoes

From seed to harvest, a guide to help backyard gardeners enjoy one of America’s favorite vegetables.

Tomatoes are the most popular vegetable in home gardens across America, according to the National Gardening Association.
(Photo: bajinda/Shutterstock)

Is there anything that tastes better than a homegrown tomato?

‘"No!" say most gardeners.

Of the 36 million households with home gardens in America, 86 percent grow tomatoes, according to a study of home and community gardening by the Burlington, Vermont-based National Gardening Association (NGA).

Of the millions of gardeners who grow tomatoes, many have developed what they undoubtedly think is the best way to grow the juicy red — or yellow or pink, or almost-black or green-striped — orb. For those who are still looking to develop their own tried-and-true method, here’s a guide for how to grow tomatoes.

Growth habits

It’s important to understand terms often seen on tomato labels. Two of those are: determinate and indeterminate.

Determinate tomatoes are the more compact of the two types, make little or no growth after fruit set and tend to bear fruit at one time. They were bred to produce a single heavy yield for canning purposes, said Anne Bailey, a Certified Naturally Grown farmer and owner of Annie Okra’s Barn in Rydal, Georgia.

Indeterminate tomatoes will continue growing to an undetermined height throughout the growing season and produce new shoots and blossoms long after the first fruit set. Indeterminate vines will bear tomatoes in all stages of development and fruit set will continue until frost.

Tomatoes are often designated by the terms early, middle and late, which refer to when the fruit will be ready to harvest. The terms are self-explanatory. Early season tomatoes are the first to ripen, late season ones are the last to ripen and middle season types fall somewhere in between. Planting some of each type is a good strategy for enjoying ripe tomatoes throughout the summer.

Choosing what to grow

Gardeners have so many tomato varieties from which to choose. (Photo: Shebeko/Shutterstock)

While tomato lovers have a seemingly endless list of varieties to plant in their gardens, tomatoes fall into three basic categories: small salad (cherry) tomatoes, slicing tomatoes and thick-walled tomatoes ideal for making sauces. An increasing number of so-called heirloom tomatoes are available among each of the three types.

Heirlooms tomatoes are those that were grown at an earlier time but for various reasons never found their way into large-scale commercial production. Often they have colorful stories. Mortgage Lifter, for instance, got its name because a mechanic in West Virginia who developed the variety made so much money selling the seeds he paid off his mortgage.

Bailey especially likes the heirlooms because she thinks they have a better taste than the modern hybrids. Of the heirlooms, Bailey says the pinks are particularly tasteful. Many of the black heirlooms coming into commerce now are from seed banks in Russia that have recently dispersed a lot of their seeds, she said. Midnite in Moscow is an example.

Hybrids picked in winter tend to be especially low in flavor because they have been picked green and exposed to an ethylene gas to give them color.

Start from seed or buy transplants

To start plants from seed, sow the seeds 8-10 weeks before the last frost date. Because spring weather can be so variable, some people allow 12 weeks from the time they start the seeds to the time they set the transplants in the garden.

Set the seeds one-quarter inch deep or less in a seed starting mix rather than in potting soil. Keep the soil moist and temperatures about 80 F until the seeds germinate. Once seedlings have germinated, they will do best with a temperature of 60 F to 70 F.

Allow the soil at the top of the pot to dry out, and then put the pot in a tray and add water to the tray. The pot will wick up some of the water and moisten the soil. After the pot has wicked up the water, empty the water from the tray. Tomatoes don’t like wet feet. Give the plants the best light you can so they will be as strong as possible. Provide supplemental light if necessary.

When to plant

When you transplant your seedlings into your garden will depend on where you live. (Photo: Cristina Sanvito/flickr)

Tomatoes can be planted outdoors in well-draining soil after the danger of frost has passed. To perform their best, tomato plants need at least six hours of sunlight. Good Friday is the traditional planting date for spring and summer gardens in many parts of the country.

Many a gardener will “cheat” on that date and plant earlier if the weather is good. But Bailey thinks it is best to wait until May to plant tomatoes. That’s because the soil is warmer later in the spring, and she believes plants put in the ground then will quickly catch up to the ones that got a slow start in the cooler soil in April. Another reason to wait until May is because unstable early spring weather patterns can send temperatures to near or even below freezing and kill plants set in the ground on the traditionally “safe” date. Growers in New England may have to wait even longer for their soil to warm up and to plant.

How to plant

Dig a hole that will accommodate two-thirds of the plant. In the bottom of the hole, add a balanced fertilizer at a rate recommended on the label or a combination of aged manure and compost. Don’t use raw manure. It will burn the plant roots. Bone meal or kelp meal can also be added to the hole. Mix the fertilizer or additives with dirt in the bottom of the hole and place the plant in the hole so that two-thirds of the plant will be below the soil surface. Fill the hole with dirt. Water thoroughly.

If transplants started from seed indoors have become leggy, lay the plant on its side, dig a hole for the root mass and a trench for the leggy stem and bury the top portion of the plant up to the first leaves. The plant will root along the stem and grow straight from the vegetative growth.

The reason to plant tomatoes deep is because roots will form along the stem and increase nutrient uptake, which will increase the plant’s vigor.

Next, mulch the plant with corrugated cardboard. Cut a hole in the center of a piece of the cardboard and place the cardboard over the plant so that the plant is centered in the hole. Lay wood chips on top of the cardboard and place one or more rocks on top of the cardboard to hold it in place. Place a stake beside determinate plants or put a cage around indeterminate ones. Stake the cage to hold it in place. Concrete wire makes the best tomato cages because it is sturdy and has large gaps that make harvesting easy.

Besides reducing the need for watering, the cardboard will create a barrier that will prevent water from splashing ground-borne diseases onto plant leaves.

Young plants

Blossom end rot is a disease that can strike young plants. (Photo: K.B.R./flickr)

The main thing to watch for in young plants is blossom end rot. This is a disease that occurs on the blossom end of the tomato (the end that is opposite from the stem) as a watery spot that may remain small or cover as much as half of the fruit. ”Using a dry form of calcium in your fertilizer program will help prevent blossom end rot,” says Rod Pittman, an Organic Farm Consultant for Veggie Patch Farm in Commerce, Georgia.

As the plants grow, Bailey likes to trim bottom leaves from the first foot of the plant. This helps reduce the risk of soil diseases entering plant leaves.

What if it turns cold?

If the temperature dips below 45 F, place a container or blanket over the plants at night. Preferably, the container should not touch plant leaves. This is also helpful if winds accompany the cold because winds can quickly dry out vulnerable young tomato transplants. Remove the protective cover the next day. Don’t use plastic. If you forget to remove plastic, heat buildup could “cook” the plants.

Days to maturity

Seed packets, catalogs and plant tags often list days to maturity. This refers to the time it takes from the day a transplant is put in the garden until the time it bears ripe fruit. For northern growers, tomatoes that require 70 days to maturity rather than 80-90 may be preferable because the growing season is shorter in Northern states than those in the South.

What if the first flowers fall off?

Don’t worry, Bailey said. It’s not well understood why this happens, she added, explaining that plants should do fine as they grow and spring weather patterns stabilize.

Suckers

Suckers are the growths that emerge between the main stem and branches. Some people like to leave them on the plant because they will flower and bear fruit, increasing yield. Some also cut them off and root them as separate plants. Others cut the suckers off as soon as they form because they believe they take strength from the parent plant. Neither method is right or wrong. Like so much about growing tomatoes, it’s a personal choice.

Pests

Two common tomato pests are aphids and white fly. Pittman controls both with a spray of one ounce of Neem and two ounces of Safer Soap combined in a gallon of water. Both ingredients are organic.

Storing

Keep freshly picked tomatoes at room temperature. Putting them in the refrigerator will cause cell membranes to break down, which results in loss of flavor.

Have other tips for how to grow tomatoes? Leave us a note in the comments below.